This invention relates generally to temporary dental prostheses and, more particularly, is directed to a temporary dental crown and a method of forming the same.
The formation of single unit temporary posterior crowns has posed a problem for dentists for many years. Generally, the methods presently being used are cumbersome, both in the actual steps that must be performed and the materials that must be used, requiring large amounts of time and high costs for preparing the crowns. In addition, conventional methods of forming temporary crowns suffer from various disadvantages, such as poor aesthetic appearance, poor marginal adaptation, imprecision in the interproximal contact areas, uncontrolled occlusal contact and physiologically inferior labial and lingual contours.
As an example, U.S. Pat. No. 2,930,124 discloses a dental crown and method of producing the same. In this Patent, a hollow cylindrical member made of metal has a plurality of projections on its inner surface adapted to secure the member to the prepared tooth. Because a cylindrical member is used, however, it is difficult to match the appearance of the crown to the adjacent teeth, whereby the aesthetic appearance is not as desirable as it should be. Further, the marginal adaptation and interproximal contact areas do not provide optimum results. The same holds true as to the labial and lingual contours and the occlusal contact.
U.S. Pat. No. 3,585,723 also discloses a dental crown and a method of installation thereof, which relies on the expansion of the cervix of the crown along the mesio-distal axis as the crown moves toward the cervical end. Because a continuous side wall is provided for the crown, the same disadvantages that accrue from U.S. Pat. No. 2,930,124 also apply to this Patent.
The same holds true with respect to U.S. Pat. Nos. 853,984 and 4,206,545, both of which disclose a crown with a continuous side wall, including mesial and distal sides, and which are affixed to the prepared tooth using a filler and cement, and the pressure of the patient's natural bite. U.S. Pat. No. 4,206,545 also teaches the use of a trimmed cervical border to adapt to the many gingival shapes present in nature.
Other patents which are less relevant than the above are U.S. Pat. Nos. 3,793,728; 3,949,476 and 4,504,230.